WATER- BLUE GOLD
With rapid population growth, water withdrawals have tripled over the last 50 years.
§ This trend is explained largely by the rapid increase in irrigation development stimulated by food demand in the 1970s and by the continued growth of agriculture-based economies.
Expected trends over the next 50 years:
§ There is still substantial uncertainty on the scale of future demands. Between 2000 and 2050 the world’s population is projected to grow from 6 billion to 9 billion, and demand for food and other goods will increase significantly.
§ The Mediterranean Action Plan is exploring possible futures for agriculture-based economies that are most vulnerable to anticipated climate change effects.
§ The world’s population is growing by about 80 million people a year, implying increased freshwater demand of about 64 billion cubic metres a year.
§ An estimated 90% of the 3 billion people who are expected to be added to the population by 2050 will be in developing countries, many in regions where the current population does not have sustainable access to safe drinking water and adequate sanitation.
§ Most population growth will occur in developing countries, mainly in regions that are already in water stress and in areas with limited access to safe drinking water and adequate sanitation facilities.
§ More than 60% of the world’s population growth between 2008 and 2100 will be in sub-Saharan Africa (32%) and South Asia (30%). Together, these regions are expected to account for half of world population in 2100.
§ By 2050, 22% of the world’s population is expected to be 60 years old or older, up from 10% in 2005. At the same time, nearly half the world population is under the age of 25.
§ Natural resource needs, including freshwater is expected to increase due to longer life expectances and globalization of trade and advertising tempting more consumption by young people in developed and developing countries.
§ The urban population is expected to double between 2000 and 2030 in Africa and Asia. By 2030 the towns and cities of the developing world will make up an estimated 81% of urban humanity.
§ By 2030 the number of urban dwellers is expected to be about 1.8 billion more than in 2005 and to constitute about 60% of the world’s population.
§ Today, there are an estimated 192 million migrants worldwide, up from 176 million in 2000.
§ Coastal areas, with 18 of the world’s 27 megacities (populations of 10 million or greater), are thought to face the largest migration pressures.
§ About 75% of people residing in low-lying areas are in Asia, with the most vulnerable being poor people.
§ The net implication of these demographic processes is clear; the world will have substantially more people in vulnerable urban and coastal areas in the next 20 years.
§ 95% of the increase in urban populations is expected in developing countries, especially in Africa and Asia, where the urban population is projected to double between 2000 and 2030.
§ WATER FOOT PRINT
§ The water footprint of an individual, business or nation is defined as the total volume of freshwater that is used to produce the foods and services consumed by the individual, business or nation. A water footprint is generally expressed in terms of the volume of water use per year.
§ Since not all goods consumed in one particular country are produced in that country, the water footprint consists of two parts: use of domestic water resources and use of water outside the borders of the country. The water footprint includes both the water withdrawn from surface and groundwater and the use of soil water (in agricultural production).
§ Virtual water is the water ‘embedded’ in commodities. Producing goods and services requires water; the water used to produce agricultural or industrial products is called the virtual water of the product.
§ The global volume of virtual water flows related to the international trade in commodities is 1,600 Km³/yr. About 80% of these virtual water flows relate to the trade in agricultural products, while the remainder is related to industrial product trade.
§ The production of 1 kilogram of:
§ rice requires 3,000 litres of water
§ maize requires 900 litres of water
§ wheat requires 1,350 litres of water
§ beef requires 16,000 litres of water.
§ 140 litres of water are needed to produce 1 cup of coffee while the production of 1 litre of milk requires 1,000 litres of water.
§ Globally, water is saved if agricultural products are traded from regions with high water productivity to those with low water productivity. At present, if importing countries produced all imported agricultural products domestically, they would require 1,600 Km³ of water per year; however, the products are being produced with only 1.200 Km³/yr in the exporting countries, saving global water resources by roughly 400 billion m³/yr.
WATER RELATED DISASTERS
§ Trends in natural disasters show they are continually increasing in most regions of the world. Among all observed natural and anthropogenic adversities, water-related disasters are undoubtedly the most recurrent, and pose major impediments to achieving human security and sustainable socio-economic development, as recently witnessed with disasters such as the Indian Ocean tsunami in 2004, Hurricane Katrina in 2005, Cyclone Sidr in 2007, Cyclone Nargis in 2008 and many others.
§ · During the period 2000 to 2006, 2,163 water-related disasters were reported globally in the Emergency Disasters Database (EM-DAT), killing more than 290,000 people, afflicting more than 1.5 billion people and inflicting more than US$422 billion in damages.
§ · The factors that have led to increased water-related disasters are thought to include natural pressures, such as climate variability; management pressures, such as the lack of appropriate organizational systems and inappropriate land management; and social pressures, such as an escalation of population and settlements in high-risk areas (particularly for poor people)
§
WATER- CONSERVE – DATA
§ Less than two percent of the freshwater on our planet exists in a readily usable form for human uses. And of this total, it is estimated that lakes contain more than 90% of all the liquid freshwater on the earth’s surface. Thus, this water source is important for meeting the needs of both humans and ecosystems, including the life-supporting services provided to humanity by the latter.
§ Lakes and reservoirs provide a range of resource values, including drinking water, irrigation water, navigation, fisheries, tourism, recreation, flood and drought management, climate mediation, as well as having religious and historic values.
§ In addition to containing the vast majority of the liquid freshwater on the surface of our planet, humans use lakes for more purposes than any other type of water system. Accordingly, lakes also are subject to more use conflicts than any other type of water system. Although seemingly a problematic feature, their effective management also a greater potential for developing sustainable solutions to water resources issues than any other type of water system.
§ In contrast to flowing rivers, lakes and reservoirs have long water residence times, an indication of the average time water will spend in a lake. Lakes with long retention times are slow to respond to many inputs, being able to absorb floodwaters and pollutants, for example, without exhibiting immediate changes.
§ Lakes also act as a sink for water and material inputs from diverse sources from their surrounding drainage basins. The mixing of these inputs within a lake ensures that the problems associated with them are disseminated throughout the volume of a lake. Thus, it is not possible for a pollutant to affect only a portion of a lake, nor is it possible to treat only a portion of a lake. Rather, water-related problems are typically lake-wide in nature.
§ Another unique feature of lakes is that they exhibit complex response dynamics. Thus, the physical, chemical and biological characteristics of lakes and reservoirs can be viewed as a type of barometer of the consequences of human activities within their surrounding drainage basin.
No comments:
Post a Comment